1. Field of the Invention
The invention relates to an electric vehicle and a performance setting method. More particularly, the invention relates to an electric vehicle including a fuel cell and a capacitor which are connected in parallel to a drive circuit of an electric motor that outputs power to an axle shaft. The invention also relates to a method for setting performance of the fuel cell and performance of the capacitor which are to be mounted on the electric vehicle that runs by supplying electric power from the fuel cell and the capacitor to the drive circuit of the electric motor that can output power to the axle shaft without converting a voltage.
2. Description of the Related Art
An electric vehicle which runs using outputs from a fuel cell and a capacitor is disclosed, for example, in Japanese Patent Laid-Open Publication No. 08-33120. It is considered that, in the electric vehicle, it is possible to obtain an output from the capacitor even when the vehicle is continuously operated under high load, by performing control such that an output from the fuel cell increases and the output from the capacitor decreases, in a predetermined acceleration continuation state where acceleration equal to or higher than a predetermined value continues for a predetermined time or longer.
However, in such an electric vehicle, there is a possibility that a fuel cell or a capacitor of inappropriate performance will be used. As mentioned above, in the predetermined acceleration continuation state, the control for increasing the output from the fuel cell and for decreasing the output from the capacitor is performed. Therefore, if the state continues, the entire output required in the state is finally supplied by the output from the fuel cell regardless of the capacitance of the capacitor. Accordingly, a fuel cell which can produce the output required to continue the predetermined acceleration continuation state is used. As a result, the fuel cell of excessive performance is used, which is not preferable in terms of energy efficiency.